Tensile strength and stiffness properties of additively manufactured PET-G polymer-based composite plates reinforced with different weight fractions of short carbon fibers

Tensile properties of composite thin-plate specimens additively manufactured from two commercially available filaments composed of PET-G polymer loaded with 15 wt% and 30 wt% of short carbon fibers (SCF) are experimentally determined, together with neat PET-G specimens tested for comparison. Relatively high overall average values of ultimate tensile strength were obtained for the SCF reinforced specimens (61.6 MPa and 52.2 MPa, respectively for specimens with 15 % and 30 % of SCF), compared to the value obtained for neat PET-G specimens (43.9 MPa). Similarly, the average value of modulus of elasticity for 15 % SCF specimens (5990 MPa) was higher than the value obtained for the ones with 30 % of SCF (4752 MPa), again both being higher than the value reached with neat polymer (1694 MPa). Scanning electron microscopy (SEM) was used to analyze specimens' fracture surfaces. SEM images of 30 % SCF specimens revealed higher presence of voids compared to 15 % SCF specimens.